Infusion devices have heretofore been suggested for use in application of various primary fluids to a patient, and such devices have commonly included a primary conduit for conveying the primary fluid from a primary fluid source to the patient. In addition, at least some such devices have heretofore utilized secondary conduits, connected with the primary conduit through a one-way valve, to add one or more secondary fluids, such as drugs, for example, to the primary fluid being infused into a patient through the primary conduit (see, for example, U.S. Pat. No. 4,447,230).
Such devices, including devices using a one-way valve, have, however, presented a problem in creating an undesirable volumetric dead space at the junction of the secondary conduit to the primary conduit. The disadvantage of creation of such a volumetric dead space is recognized in U.S. Pat. No. 4,439,182, and the device described therein attempts to minimize the created dead space.
It should therefore be appreciated that further improvements in valving apparatus to substantially preclude formation of volumetric dead space at the junction of the primary and secondary conduits is desirable.